## Index of list lisp

So I have a list of integers and I'm trying to find the index where . list(i) > list(i+1) I have the base cases where if the list is empty or length 1, it returns the list length, but I'm having trouble with actually traversing the list and keeping track of the index.

In Common Lisp the operator that gets the n-th element of a list is called nth (see the manual): (nth 2 '(a b c d)) ; returns C. A related operator is  5.3 Accessing Elements of Lists. — Function: car cons-cell. This function returns the value referred to by the first slot of the cons cell  start, end---bounding index designators of sequence. The defaults for start and end are 0 and nil, respectively. key---a designator for a function of one argument, or  Function LIST, LIST*. Syntax: list &rest objects => list. list* &rest objects+ => result . Arguments and Values: object---an object. list---a list. result---an object. Emacs Common Lisp Emulation Manual. dash.el has a function that can do this: - elem-index. (-elem-index 2 '(6 7 8 2 3 4)) ; (defun nth-elt (element xs) "Return zero-indexed position of ELEMENT in list XS, or nil if absent." (let ((idx 0)) (catch  Common Lisp the Language, 2nd Edition. next · up · previous contents index. Next: Alteration of List Up: Lists Previous: Conses. 15.2. Lists. The following

## In LISP, an array element is specified by a sequence of non-negative integer indices. The length of the sequence must equal the rank of the array. Indexing starts from zero. For example, to create an array with 10- cells, named my-array, we can write −

7. car , cdr , cons : основные функции. В Лиспе самыми основными функциями являются car , cdr и cons . Функция cons используется чтобы создать  CLiki is a Common Lisp wiki hosted by The Common Lisp Foundation. Lisp Libraries (Don't forget to check out the current recommended libraries list). 4 Jun 2013 See the ANSI Common Lisp section on the defun macro (defun elt (list index) " Returns the index'th element of list, or nil if there isn't one. 6 мар 2007 Если вызвать cons с типом nil , Lisp считает nil пустым списком и создает список с одним элементом. append соединяет два списка. list  30 Jan 2008 However, for historical reasons, lisp's list is based on the hardware Each element has 2 parts, one being the node's index, and the other  So I have a list of integers and I'm trying to find the index where . list(i) > list(i+1) I have the base cases where if the list is empty or length 1, it returns the list length, but I'm having trouble with actually traversing the list and keeping track of the index.

### I have been searching everywhere for the following functionality in Lisp, and have gotten nowhere: find the index of something in a list. example: (index-of item InThisList) replace something at a specific spot in a list. example: (replace item InThisList AtThisIndex) ;i think this can be done with 'setf'? return an item at a specific index

I've seen ziele's other posts and hes far good at LISP, Stefan has some scary skills aswell, same as Rlx, Roy also seems far experienced, although they all have relatively small count of posts comparing to their skills. And I think that applies to you aswell, maybe the reason is experience from native lisp forums? In the simplest case, listname is an unquoted symbol naming a list; in that case, this macro is equivalent to (prog1 (car listname) (setq listname (cdr listname))). x ⇒ (a b c) (pop x) ⇒ a x ⇒ (b c) The position returned is the index within sequence of the leftmost (if from-end is true) or of the rightmost (if from-end is false) element that satisfies the test; otherwise nil is returned. The index returned is relative to the left-hand end of the entire sequence, regardless of the value of start, end, or from-end. I search a simply lisp routine which change only one element (index of this element is famed). for example: I want change second element of list: DATA=(A B C B D) second element is B (index=1) new element is X my function must return (A X C B D) (namefunction DATA 1 X) -> (A X C B D) >>> any ideas?

### In LISP, an array element is specified by a sequence of non-negative integer indices. The length of the sequence must equal the rank of the array. Indexing starts from zero. For example, to create an array with 10- cells, named my-array, we can write −

The list function is rather used for creating lists in LISP. The list function can take any number of arguments and as it is a function, it evaluates its arguments. The first and rest functions give the first element and the rest part of a list. The following examples demonstrate the concepts. I have been searching everywhere for the following functionality in Lisp, and have gotten nowhere: find the index of something in a list. example: (index-of item InThisList) replace something at a specific spot in a list. example: (replace item InThisList AtThisIndex) ;i think this can be done with 'setf'? return an item at a specific index In Common Lisp is it (nth index list), with index starting from 0. – Renzo Mar 21 '16 at 10:52 In LISP, an array element is specified by a sequence of non-negative integer indices. The length of the sequence must equal the rank of the array. Indexing starts from zero. For example, to create an array with 10- cells, named my-array, we can write − I've seen ziele's other posts and hes far good at LISP, Stefan has some scary skills aswell, same as Rlx, Roy also seems far experienced, although they all have relatively small count of posts comparing to their skills. And I think that applies to you aswell, maybe the reason is experience from native lisp forums? In the simplest case, listname is an unquoted symbol naming a list; in that case, this macro is equivalent to (prog1 (car listname) (setq listname (cdr listname))). x ⇒ (a b c) (pop x) ⇒ a x ⇒ (b c) The position returned is the index within sequence of the leftmost (if from-end is true) or of the rightmost (if from-end is false) element that satisfies the test; otherwise nil is returned. The index returned is relative to the left-hand end of the entire sequence, regardless of the value of start, end, or from-end.

## (defun insert-at (item list index) (destructuring-bind (left right) (split list (1- index)) ( append left (list item) right))) ;; Smartass solution, using Common Lisp, sharing

An assortment of (usually) standalone Lisp functions that deal with list manipulation, working Returns the index of the first occurance of a top level item in a list. (defun insert-at (item list index) (destructuring-bind (left right) (split list (1- index)) ( append left (list item) right))) ;; Smartass solution, using Common Lisp, sharing  Symbol class: Sequences (Lists, Strings) and Arrays. Syntax: Symbol type: Return value is index of such item or NIL if item is not found. Index is relative to start  In computer programming, CAR ( car ) /kɑːr/ ( About this sound listen) and CDR ( cdr ) are The tag specified one of three index registers. In Lisp, however, the cons cell is not used only to build linked lists but also to build pair and nested   Almost all clauses use the syntax of function keyword-argument lists: alternating keywords and arguments. iterate keywords don't require a preceding colon, but  (concatenate 'list) ; no argument sequences NIL ? (concatenate (subseq '(1 2 3 4 5) 0 3) ; element at ending index is not copied (1 2 3) ? (subseq #(#\a #\b #\c

(concatenate 'list) ; no argument sequences NIL ? (concatenate (subseq '(1 2 3 4 5) 0 3) ; element at ending index is not copied (1 2 3) ? (subseq #(#\a #\b #\c  Related to last in lisp lisp index. Related packages. The third, optional, argument is the index of the first character which is not a part (format nil "This is a string with a list ~A in it" '(1 2 3)) "This is a string with a list  In other words, don't worry about an out-of-bounds index. Your function must be recursive. (nth 2 '(joe bob bill)) => bob. (defun nth (n list)